Determination of several trace metals in simulated fresh water by graphite furnace atomic emission spectrometry

Analyte ionization in graphite furnace atomic absorption spectrometry

“…It can also be seen from Figures 2-5 that ionization of Li, K, Rb, and Cs in the graphite furnace at 2300 °C is not significant from the viewpoint of atomic absorption, but ionization interference should be taken into consideration for K, Rb, and Cs when atomic emission signals are measured. This conclusion is in agreement with that drawn by Epstein et al (4,5). Addition of excess Cs as an ionization suppressant for Li, K, and Rb and addition of excess Rb as an ionization suppressant for Cs increased the atomic emission signals (time integrated net intensity) for K, Rb, and Cs but had no effect on (for K) or suppressed the atomic absorption signals (Rb and Cs-possibly as a consequence of matrix interference for these two elements).…”

“…T Vian + log z log ne-+ 15.684 (5) where K{(T) is the ionization constant, a¡ is the degree of ionization, n is the number density of the species indicated by the subscript, e~M and e"f are electrons derived from ionization of the metal and from other sources within the furnace, respectively, Vion is the ionization potential (eV), T is the absolute temperature, and Za and Z¡ are the partition functions for the atom and ion, respectively. The magnitude of the ionization constant, K^T), depends on the temperature and the element but not on its concentration.…”

Atomic emission spectrometry with metal microtube atomization

“…Matousek et al (7) studied furnace emission for Li. Epstein et al first used wavelength modulation to correct for furnace background emission (8) and determined Cu, Mn, Ba, Al, Mo, Ni, and Be in NBS standard samples by graphite furnape atomic emission spectrometry (9).…”

Evaluation of a Direct-Current Argon Plasma as a Primary Pseudocontinuum Radiation Source for Wavelength-Modulated Atomic Absorption Spectrometry

“…Moreover, the self-reversed emission profiles of resonance lines for the six elements studied were asymmetrical, with an intensity shift toward shorter wavelengths. Asymmetry of self-reversed lines has been observed in emission from hollow cathode lamps (16)(17)(18)(19), inductively coupled plasmas (20,21), and graphite furnaces (22). An emission profile with such complex curvature required careful manipulation of the wavelength modulation interval and the plasma viewing region so that the average intensity from the emission profile within the modulation interval produced a nulled (i.e., net zero intensity) lock-in amplifier signal.…”